Melt butter in a medium saucepan and cook until browned bits begin to form. Continue cooking, scraping the bottom, until butter is dark brown but not burned. Allow to cool, but not congeal.

In a food processor, pulse almonds until finely ground. Add flour and pulse until combined. Place in a medium-sized bowl and add powdered sugar, whisking to combine. In a separate bowl, whisk egg whites until soft peaks form. Fold into flour mixture. Then fold in honey and then butter.

Place liners in mini-muffin cups. Spoon about 1 tablespoon of batter into each; top with 1 or 2 blackberries. Bake about 15 minutes.

Let cool in pan for 10 minutes. Dust with powdered sugar just before serving.